Biochemical and structural studies of histocompatibility antigens, tumor antigens, transformation related antigen (p53) and epoxide hydrase. It is the purpose of this project to study the chemistry and structure of different molecules. Biochemical isolation of histocompatibility antigens, transformation related protein (p53), tumor antigens and epoxide hydrase is carried out. The chemical structure of these proteins is being approached by micro methods and the relationship of the amino acid sequence to other known structures is being analyzed. Cloning of histocompatibility antigens, beta2 microglobulin and the p53 protein is being approached in order to study the molecular organization of these systems and permit a better understanding of the nature of the extensive polymorphism at the H-2 loci and the mechanism involved in the regulation and expression of different genes.